1. Field of the Invention
The present invention relates to railway hopper cars. More specifically it relates to door opening and closing mechanisms for the bottom dump doors of the car.
2. Description of the Prior Art
Pertinent patents of the prior art include U.S. Pat. Nos. 1,594,863 Aug. 3, 1926; 1,781,259 Nov. 11, 1930; 3,321,093 May 23, 1967; 3,452,886 July 1, 1969; 2,616,576 Nov. 4, 1952. U.S. Pat. No. 1,594,863 to Warner discloses a longitudinal bottom dump car with gate structures opened by rollers. U.S. Pat. No. 1,781,259 to Welsh et. al. discloses discharge mechanism for cars or tubs for hauling coal in coal mines, the tubs are interconnected for discharge. The patent to Arbel, U.S. Pat. No. 3,321,093 discloses a latching arrangement for hopper car doors as does the patent to Dorey, U.S. Pat. No. 3,452,886. Sanford's et. al. U.S. Pat. No. 2,616,576, discloses electric switches which, when simultaneously activated, act to unlock hopper car doors. The present construction is an improvement over the aforementioned patents, in that it discloses vertically reciprocally mounted plungers connected to the hopper structure by tubular guides. The plungers are actuated from ground-mounted camming arrangements in turn actuating door latches to an open position. This is not disclosed in the aforementioned prior art patents.